www.ijsret.org 287 International Journal of Scientific Research Engineering & Technology (IJSRET), ISSN 2278 – 0882 Volume 4 Issue 4, April 2015 Strength Analysis of Aluminosilicate Soils for Use in Brick Manufacturing Expedito Milyaso 1* , Arthur M. Omari 2 , Baraka Kichonge 1 1 Arusha Technical College (ATC), Mechanical Engineering Department, P.O. Box 296 Arusha, Tanzania 2 Mbeya University of Science and Technology (MUST), P. O. Box 131 Mbeya, Tanzania ABSTRACT The study analysed the strength of selected aluminosilicate soils for possibility of use in brick manufacturing. The soil samples included in the analysis were from River Natron, Lake Natron, Oldoinyo Lengai, Mto wa Mbu, Lokii and Kisongo. Similarly, trona was used as a catalyst while Holili and Uchira blocks were for comparative strength analysis. The analysis showed that the compressed aluminosilicate bricks are viable option for use as construction material. The achieved compression strength is enough for construction of building blocks for unsheltered single storey houses in low wind areas. The bricks have shown increasing compression strength character with time, within the 7 to 90 days of investigation at room temperature. There exists a good correlation between the maximum compressive strength and the maximum amount of combined aluminosilicates. The higher the amounts of silica and alumina produced a better strength. Comparable results are demonstrated by the composition of Uchira and Holili bricks. Natron aluminosilicate soils has extremely long setting times, but on activation by an alkaline material (Trona) this time can be reduced. The SiO 2 /Al 2 O 3 ratio of the fabricated bricks is very nearly 1:1 suitable for bricks, ceramics and fire protection. Keywords - Aluminosilicate, alkaline, geopolymer, silica, trona, compression strength I. INTRODUCTION Building bricks requires certain strength in order to qualify for construction. Various materials are used for manufacturing of construction bricks however they are associated with processes which are not environmentally friendly. The present manufacturing processes of cement and bunt bricks have a great effect on the environment. The emission of greenhouse gases from high temperature techniques used during production of cement causes depletion of ozone layer resulting into global warming [1]. Bricks made using clay are burnt at a temperature of about 1000ºC to achieve the required strength [2, 3]. According to Building Research Unit of Tanzania (BRU 1981) the minimum strength requirement for building blocks for single storey houses are classified into three classes that varies according to the wind conditions on the site as Class A, B and C. Class A applies to hard wind areas for buildings that are not sheltered by other buildings with minimum brick strength of 2.5N/mm 2 whereas Class B applies to hard wind areas for buildings that are sheltered or to low wind areas for buildings that are not sheltered with minimum brick strength 1.5N/mm 2 . Class C minimum brick strength is 1.0N/mm2 and it applies to low wind areas for buildings that are unsheltered. British Standards Compression Strength Requirements for Mortars (BS 5628 Part1: 1978) recommends the minimum compressive strength for solid bricks having a ratio of height to least horizontal dimension of between 0.6 - 2.0 is 2.8N/mm 2 . Aluminosilicate materials are ceramic like inorganic polymers that are based on silica and produced at low temperatures [4]. They are considered to be strong, fire and acid resistant [5]. They can easily be produced by casting or extruding. Aluminosilicate based bricks use cheap material abundantly available naturally in some areas, e.g. lateritic clay earth [6]. These materials mixed with a simple geopolymer binder are compressed to give the shape of a brick and thus can be termed as geoplymer materials [7]. The main objective of this study is to analyse the strength of selected aluminosilicate soils for possibility of use in brick manufacturing. The study output will contribute to the body of knowledge that exists in Tanzanian soils. Furthermore, the study results will assists in conservation of environment by providing an alternative method in bricks manufacturing for construction purposes thus replacing harmful traditional methods.